I changed those values in that cts subtrator table so that they are much lower at cold temps. I am going to work in half an hour, so I will post up if it helps, or hurts at all!

 

I lowered all of the values in the subtractor table from 180 degrees and below, and cut the values in half, and it did absolutely nothing. My idle is still at 2200 rpm any time I get to a stop light, or push in the clutch while moving.

So, that did not help at all, any other ideas?

--mark

 

sorry to hear that. I'm under the impression this is a software/ROM bug and not something that can be tuned or adjusted out. reason being is that, on my car atleast, the high idle is not repeatable. Sometimes it will do it and others it won't. there is no ryhme or reason it happens.

 

Hopefully we can get the ear of tephra and the other gurus, and they can take a look at this!

 

Possible Solution!

After no success in the CTS Subtractor table, I looked at the Idle section of the Tephra map, and saw that my target idles were all around 1398 and below, so that was not the cause. I then looked at the default stepper targets in neutral and driving, and noticed that there is a huge difference between cold temps and 180 degrees. I tried lowering the values for both neutral and moving, and when I tested it, my idle dropped down to 1500 rpm or lower. So, it may have worked, I need others to confirm though.

Here are the before and after screenshots of those tables:

Before


After


Can someone else please try altering these values as well, and see if it helps fix the problem. That would be great.

Thanks!

--mark

 

I will double check my values on those tables, but I think they're even lower than yours...

 

What you did is what I've done successfully to get cold to warm up idle RPM in check.

 

I already pointed out those tables. The other table is the percent of the steps in those tables that actualy get used. I would suggest logging your ISC Steps. Those tables will help but the first table that I pointed out is like a master table so to say. The numbers in those tables x the % in the first table is how many steps its gonna open.

I mean do whatever works for you, but are you sure you used the general table not the startup table?

 

those are the tables i was talking about that i mentioned in here.. i used those same tables to fix the issue on my car also. see post #14

Yes it works and you can also adjust those tables to make the car have a smoother shift also.

 

Did you make your values similar to mine, or are they quite a bit different?

 

not really, but i have a 2.3L it has higher airflow per rev. Desired ISCV intial step position with AC off-Neutral is all you need to really adjust. i didnt touch the drive one.

mine are:

145
125
110
95
78
53
13
7

be careful how much you adjust it, you can create idle surge.

i think you already figured out the trick to getting the shifts really smooth tho right? based off your picture. 9417 rom really shifts crappy with the default iscv, the 9653 one is much better.

 

Actually no, but mine doesn't seem to shift too bad (but I shift fast, even daily). What should I look for and change for better shifting.

P.S. Thanks for the help, I'm learning tons here. I tune Megasquirt, but most of this stuff is new to me!

 

what rom ID are you using? sorry if you already mentioned it, but i didnt see.

 

I'm on 94170715

 

same one i use for my car.. so you never felt any notchiness when shifting before altering those values at all vs now?

heres the settings i give for customers on that rom with a 2L

145
128
122
113
95
53
13
7

those settings seem to make shifting smoother + will cure the high idle startup.

if you try the settings i use on my personal car on your 2L it will idle surge.